Automatic safety device for pottery machines



May 13, 1930. w. J. MILLER 1,758,084

AUTOMATIC SAFETY DEVICE FOR POTTERY-MACHINES Original Filed March 9, 1927 2 Sheets-Sheet l ATTORNEY y 1930- W..J. MILLER 1,758,084

AUTOMATIC SAFETY DEVICE FOR POTTERY MACHINES Origifial Filed March 9, 1927 2 Sheets-Sheet 2 mJM/ler ATTOR Extery fabricating Patented May 13, 1930 PATENT OFFICE WILLIAM J. MILLER, OF SWISSVALE, PENNSYLVANIA AUTOMATIC sarn'rv nnvrcn FOR Portraits? mciz nms Application fil ed March 9, 1927, Serial No- 173,994. Renewed October 27,

My invention relates'to improvements in pottery machines 1n general, and more particularly to such as described in my application for patent for mold conveying and gritmechanisms, Serial 0.

159,395, filed January 6, 1927, which has become Patent N 0. 1,697,993, dated Jan. 8, 1929.

One of the objects of my improvement isto prevent damage to the machine or any part thereof, due to erly through .eling frame,

accidental stopping or overrunning of certain of the working parts of the machine. t

Another object of my improvement isto automatically discontinue the reciprocation of the jiggers when the conveying mechanism of the machine fails to function properly, and also when the pressure between the profiles and the charge ofmaterial on the molds becomes excessive.

Among other features, the machine includes'instantly acting electrical devices to automatically discontinue the said reciprocation of the jiggers, and also a reliable mechanical device or mechanism for co-operating with said electrical devices and also to replace them, when they fail to function propsome unforeseen cause, whereby the functioning of the safety devices as a Whole is doubly assured and provided for.

A further object of my invention isto provide a means for discontinuing the rotation of the shaft, which actuates the machine, said means to be actuated by a departure operation of the machine, and said means to remain inactive when the operation of the machine is normal.

A still further object of my improvement isto have my above automatic safety devices for pottery machines simple, durable, and inexpensive.

Other objects and advantages willhereinafter appear.

I attainthese objects by the devices and mechanisms, which are illustrated in the accompanying drawings, or by any mechanical equivalent or obvious modification of the same.v The drawings illustrate-the invention applied: to a machine wherein the jigger mechanism is mounted on a movable or travbut it will be obvious that the invention may be applied to, and function in connection with a machine wherein the jig er mechanism is stationarily mounted, such or example as the machine illustrated in my copending application Serial No. 202,629, filed June 30, 1927, for conveying mechanism.

In the drawings Fig. 1 1s a fragmentary plan view of the machine; and Fig. 2 is a side view, looking from left to right in Fig. 1. Fig. 3 is a detail on a larger scale of the terminal and switch contact members and their supports, which are hereinafter described.

Like numerals refer to like parts throughout the several views:

11 designates vertical able jigger frame 10 of a pottery machine, such as described in my above noted patent, and 12 a horizontally disposed cover frame, which has thereon sockets 13, which are slidably mounted on said members 11, for a purpose, which is hereinafter described.

Oppositely extending spurs 14 and 15 are shown as provided on some of said sockets 13.

members of a mov- Each 'of said spurs 14 has at the end thereof an insulated terminal and switch contact member 16, f

or connecting thereto electric wires a,

which lead to the electric motor 76. The motact member 17, for connecting thereto elec- Y trlc wires 6, which lead to an electro-magnetic' brake 75, to act on a disc on said shaft 30.

Beams 18 are shown as secured to the upper ends of some of the members 11, and they have adjustably suspended therefrom, by means'of nuts 19 and safety nuts 20, vertical rods 21.

A sleeve 22 is slidably mounted on each of said rods 21 and supported in position by means of a collar 23 thereunder, which is adjustablysecured to each of said rods21 by means of a suitable set screw.

Said sleeves 22 may be kept from rotation on said rods 21 by means ofsuitable keys or splines therebetween, which are not shown in the drawings.

S rings 86 are interposed between the underside of the beams 18 and the top of the sockets 13, thereunder, for a purpose, which is hereinafter described.

A collar 90 is shown in Fig. 1 as adjustably secured by means of a screw 92 to the upper end of each of the other members 11, which has no beam 18 thereon, and springs 86 are also interposed between the underside of said collars 90 and the top of the sockets 13 thereunder, for a purpose which is hereinafter described.

The sleeve 22 has thereon a horizontal 'projection 24, which tween said spurs the end thereof an insulated terminal and switch contact member 25, for electric wires 0, which lead to a source of electric power such as an electric generator or an electric main.

Each of themembers 16, 17 and 25 has thereon a metal contact for electrically connecting said wires 0, b and 0 to each other when any two of said contacts are brought into touch with each other.

When the machine is in operation the cover frame 12 is positioned above the ends of the mold carrying pallets 26, which are described more in detail in my above co-pending application. The wires 0 of the member 25 on the projection 24 are electrically connected to the wires a of the terminal and switch contact members 16 on the spurs 14, thereby supplying current to the motor 76, which operates primarily to impart reciprocation to the jigger spindles 27, which have chucks 29 thereon, and movement to the jigger frame 10 of the machine.

A compression spring 28 is interposed between the undersideof each of the beams 18 and the top of the sleeves 22, for a purpose, which is hereinafter described.

Brackets 87, which have thereon sliding blocks 88, are mounted on the cover frame 12; said blocks 88 have adj ustably secured thereto profiles 89.

The brackets 87, blocks 88 and profiles 89 normally operate substantially as described in my co-pending application for patent for Machine for use in the manufacture of pottery ware, filed November 17, 1926, Serial No. 148,872.

When the motion of the travelling jigger frame 10 of the machine is accidentally either stopped, advanced or retarded with relation to the pallets 26, the chucks 29 on the jigger spindles 27 are thereby brought out of registration with the pallets 26 and strike the underside of the same, thereby raising said pallets above their normal level, whereupon the cover frame 12 with the sockets 13 thereon will be raised by the pallets 26, thereby raising the spurs 14 with the terminal and switch contact members 16 and wires a thereon out of contact with the terminal and switch contact member 25 and the wires 0 on the projecextends into the space be-' 14 and 15, and it has at' cause the cover plate 12 tion 24. The current will then be cut off from the motor 76.

The cover frame 12 with the sockets 13 thereon may also be raised by an excess of pressure between the profiles 89 and the material on molds 91, which are supported by the chucks 29 during the operation of profiling, thereby producing the same effect as the raising of the frame 12 by the pallets 26.

The springs 86 act to return the cover frame 12 to its original position after the cause of the said excess of pressure has been removed; they also serve to make the pressure between thexprofiles 89 and the material on said molds res' ient.

The motor 76 may, however, continue to revolve by momentum, thereby causing the chucks 29 still further to raise the pallets 26 with the cover frame 12 thereover. This will cause a further rise of the sockets 13 with the spurs 15 thereon, thereby bringing the insulated terminal and switch contact members 17 with the wires 7) thereon into electrical connection with the wires 0 on the terminal and switch contact members 25 on the projections 24, whereby current may be supplied to an electromagnetic brake 75, which may be so positioned as to exert a retarding force on a disc 85, secured to the shaft 30, which is employed for reciprocating the spindles 27, thereby quickly stopping the same.

Any further rise of the frame 12 by means of the chucks 29 will cause the spurs 15 to press on the projections 24 upwardly, thereby raising the sleeves 22 on the rods 21 against the force of the springs 28, which serve to maintain the contact between the members 25 and 17 and to prevent the fracture of the projections 24 or spurs 15.

The chucks 29 serve to intermittently raise the molds 91 from the pallets 26, to bring them into operative position under the profiles 89, as described more in detail in my last mentioned co-pending application.

Vhen the mold 91 happens to be misplaced, or when a higher mold is erroneously placed in position instead of a lower one, an excess of pressurewill be produced between said mold and the profile 89, which will also to be raised, thereby bringing into action the above described means for disconnecting the motor 76 and applying the brake 75.

The shaft 30 operates to impart reciprocation to'the jigger spindles 27 and motion to the sprockets 31, which engage the chains 32 and advance the pallets 26, as is described in my above co-pcnding application.

The shaft 30 is actuated by the electric motor 76 in a way which is hereinafter more fully described.

A clutch 33 34, which consists of two parts 33 and 34,is provided, for normally comecting the shaft 30 to the electric motor 6.

v against the part 34,

' The part 33 of said clutch isin s'pline'sliding engagement with the shaft 30, and the part 34 is swivelled on the same shaft.

A spring 35 is abutting at one end thereof 5 against a collar 36, which is adjustably secured to the 'shaft 30 by means of a suitable set screw, and at the other end thereof against the rear of a sleeve 37, which is made in one with the part 33, thereby pressing said part which is kept from longitudinal displacement on the shaft 30 by means of two collars 38 and 39, which are placed one on each are secured to the shaft 30 bymeans of suit- 15 able set screws as shown.

A stepped pulley 40 is formed on the part 34, for a belt, whereby it may be operatively connected to the motor 76, thereby actuating the shaft 30. c

A forked yoke 41 is slidably engaged in a groove 42 in thesleeve 37; the latter rotates on the yoke 41, and may be shifted thereby on the shaft 30, whereby the part 33 may be moved out of contact with its counterpart 25 34, as is hereinafter described.

The yoke 41 is adjustably secured to the end of a horizontal rod 43 by means of nuts 44 and 45 on a threaded portion 46 on the rod 43. y

A bell crank lever 47-48 is pivotally connected at its bend or elbow to the frame of the machine at 50 and has its vertical arm 47 operatively connected to the rod 43 by means of a bifurcation 56 at the end of the 35 arm 47, which bestrides the rod 43, and a collar 49, which is shown as adjustably secured to said rod at the left side of the bifurcation 56 in Fig. 2 of the drawings, by means of a suitable set screw. The collar 49 takes up the thrust of the arm 47, to move the rod 43 in a direction to drawings, and it returns the arm 47 to its original position when said rod is moved in a direction to the right in Fig. 2 of the drawings under the influence of the spring 35, the sleeve 37 and the yoke 41.

The horizontal arm 48 of said crank lever is pivotally connected at '54 to the lower end of one section 51 oh). vertically disposed connecting rod 51-52, which consists of two sections 51 and 52, which are adj ustably connected to each other by means of a union 53, and suitable right and left threads at the adjacent ends of said sections. y

The upper end of the section 52 is pivotally connected at 55 to the cover frame 12, as shown;

Any upward motion of the cover frame 12, as above described, will be transmitted by means of the connecting rod 51-52 and the bell crank lever 47,-48 to the collar 49 and rod 43, thereby moving the latter to the left in Fig. 2 of the drawings, thereby causing the yoke 41 to shift the sleeve 37 85 and part 33 of said clutch out of engageside, of the part 34 and the left in Fig. 2 of the ment with the part 34 thereof, whereby the shaft 30 will be mechanically disconnected from the motor 76, which actuates the same. The shifting of the sleeve 37 and part 33, as above mentioned, is done in opposition to the force of the spring 35, which causes the sleeve 37 to return to'its original position when said cover frame 12 is allowed to descend, as when the machine is brought into normal condition again by the removal of the cause of the disarrangement; the sleeve 37 and yoke 41 then cause the rod 43 with the collar 49 thereon to move in a direction to the right in Fig. 2 of the drawings; the collar 49 is then kept by the influence of the spring 35 in contact with the bifurcation 5 on the arm 47 of the bell crank lever 4748, when the latter is returned to its normal position by means of the weight of the frame 12 and the connecting rod 51-52.

The rod 43 or the arm 47 preferably the latter, may also be connected by means of a lever of the first class to a suitable belt shifter, to remove the'belt from the stepped pulley 40, said shifter moving in a direction from left to right in Fig. 2 of the drawings when the rod 43 and arm 47 are moving in the opposite direction, to disconnect the clutch 3334;

the said shifter may be designed to work only in one direction, to wit: to throw the belt 01f of the pulley 40, without pulling the belt on to said pulley again.

The above means for disconnecting the motor fromthe shaft 30 by th belt from the stepped pulley 40 may be employed as an additional precaution in case some part of the above described clutch connecting means fails to function properly, as when the collar 49 may get loose on the shaft 30, also to prevent the premature restoration of the connection of said shaft with the electric motor 76 by means of the weight of the e removal of the.

frame 11, through the pressure of the spring.

35, as hereinbefore described, or through any other cause.

A bracket 57 which terminates at its. upper end in a suitable brake shoe 58, is secured to the frame of the machine by means of suitable fastenings as shown. Said shoe is positioned to intercept the part 33, when the latter is moved from right to left in the drawing, as hereinbefore described, to limit the travel of said part in that direction and also to engage the rear of said part and to act onit as a brake, whereby the rotary motion of the shaft 30, which may beproduced by the momentum of the parts secured'thereto, may be quickly stopped.

The toothed member, if desired, to form a jaw clutch with the rear of the part 33, which may also be provided with teeth, to mesh with said member.

The rod 43 is shown as adjustably connected to another rod 59, which is in line brake shoe 58 may be replaced by a therewith,by means of a union and right and left threads on the contiguous ends of the rods 43 and 59, thereby forming one connecting rod of adjustable length, as shown.

The outer end of the rod 59 is pivotally connected at 61 to an oscillating arm 62, which is pivotally connected at the lower end thereof to a part 64 of the stationary frame 77 of the machine, which is described in my above co-pending application.

The upper part of the arm 62, as seen in Fig. 2 of the drawings, extends in front of a double contact switch plate 65, which is se cured to a stationary part 78 of the machine,

and has mounted thereon a pair of insulated terminal and switch contact members 66, which have thereon wires 0, which lead to a source of power, and suitable contacts, for electrically connecting said wires 0 to other wires, which are hereinafter described.

The switch plate 65 has thereon two pair of insulated terminal and switch contact members 67 and 68, one pair on each side of the arm 62, as shown in Fig. 2. The members 67 are secured to the switch plate 65. The members 68 are slidably connected to stationary posts 79 on the plate 65 by means of extension stems 80 at the rear of the members 68 and sockets 81 in the posts 79.

Springs 82 are interposed between the posts 79 and the members 68, to keep the latter in position and to afford a resilient contact to said members with the members 66 on the arm 62 when the latter is moved to the left in Fig. 2 of the drawings.

Nuts 83 on threaded portions 84 at the end of the stems 80 limit the motion of the members 68 to the right in Fig. 2 of the drawings under the influence of the springs 82.

The members 67 have thereon wires (1, which lead to the motor 76; the members 68 have thereon wires 6, which lead to the brake 75, which is hereinbefore described.

The members 67 and 68 have thereon also contacts, for electrically connecting the wires a and b to the wires 0 on the members 66.

It is evident that the motion of the rod 4-3 in a direction fromright to left in Fig. 2 of the drawings will swing the arm 62 in a direction to bring the wires 0 into electrical connection with the wires 6, thereby applying the electro-magnetic brake to the shaft 30, and the motion of the rod 43 in the opposite direction will swing the arm 62 in the opposite direction, thereby electrically connecting the wires 0 with the wires a, after disconnecting the wires 0 from the wires 7), thereby disconnecting the brake 75 and thereby starting the motor 76.

The said brake is also provided to act independently of and in addition to the commercial electric brake, which is supplied with certain standard motors and which acts to instantly arrest the revolution of the motor when the electrical current, passing through the latter, is discontinued.

In this way an additional provision is made for sto ping the motor 76 by the raising of the cover rame 12 by means of the chucks 29 on the s indles 27, in case the clutch 33-34 should ail to disengage the shaft 30 from the motor, and for starting the motor again by the lowering of the frame 12.

To prevent the over-running of the movable frame 10, which may be due to any failure of the means for disconnecting the same from the chain 32, as described ljl my above first mentioned copending application, or to any other cause, I provide an automatic electrical means for stopping the motor 76, which primarily controls the movement of the shaft 30, sprockets 31 and chains 32, thereb automatically discontinuing the tractive e ort on the frame 10, which has a very slow motion and an inappreciable momentum, and which is, therefore, readily brought to a standstill.

I also combine this automatic electrical means for stopping the motion of the frame 10 with the hereinbefore described mechanical means for automatically disconnecting the shaft 30 from the motor 7 6, thereby simultaneously discontinuing and stopping the reciprocation of the spindles 27.

The above automatic electrical means comprise a horizontally disposed bolt or member 70, which is adjustably connected to a flange 71 on the frame 10 by means of a nut 72, in contact with the flange 71, which is tapped, and a thread at one end of the member 70, which terminates at the other end thereof in a head 73, and is so positioned as to be interceptedv by the upper end of the arm 62 when the frame 10 is over-running, thereby swinging the arm 62 on its pivot 63 from the position shown in Fig. 2 of the drawings to the left thereof on the switch plate 65, thereby breaking the contact of the members 66 and wires 0 thereon with the members (-7 and wires a thereon and making a contact between the members 66 and the wires 0 thereon with said members 68 and wires b thereon, thereby disconnecting the motor 76 from the source of power and connecting the electromagnetic brake 75 thereto, thereby discontinuing the current in the motor 76 and thereby quickly stopping the shaft 30 with the sprockets 31 and the chains 32 until the derangement of the machine is corrected, whereupon the arm 62 may be manually swung to its original position, to reconnect the motor 76 to its source of power and re-start the machine.

The said swinging of the arm 62 by the bolt 70 to the left in the drawings also causes the rods 59 and 43, with the yoke 41 to move the sleeve 37 with the part 33 of the clutch 33-34= to the left in Fig. 2, thereby disconnecting the clutch 33-34 and thereby mechanically disconnecting the shaft 30 from the motor 76.

v A handle 74 is provided at the upper end b of the arm 62, or manually swinging the same as above described.

The hereinbefore described means for preventing over-running of the movable frame 10 may also be employed for normally bringing said frame to a standstill, instead of the m means for disconnecting said frame from the chain 32, as described in my above first mentioned co-pending a pli'cation, if desired;

The proper point or making and breaking the hereinbefore described contacts of my automatic safety devices for potter machines,

as well as for applying the mec anical disconnecting means, which are hereinbefore described, may be controlled b regulating the sundry adjustin means of the various parts of said safety evices, as hereinbefore described.

Theelectric motor 76 in my above automatic safety devices for pottery machines may be replaced by any other source of power,

such as a steam engine, a gas engine or a line shaft, and the hereinbefore described movable insulated terminal and switch contact members may be replaced by suitable stop valves for said gas and steam engines or with belt shifters and clutch disconnecting means forsaid line shafts, in addition to the mechanical disconnecting means, which are hereinbefore described in detail.

Many other changes may be made in my automatic safety devices for pottery machines, without departing from the main scope of my inventlon, and parts of my invention may be used without other parts;

I do not, therefore, restrict myself to the details as' shown and described; but I intend to include also all mechanical equivalents and obviousimodifications of the same within the scope of my invention.

.1 claim as my invention, and desire to secure by Letters Patent:

1. A pottery machine including of mold carriers, reciprocating jlgger mechanism adapted to cooperate with said carriers, means for conveying said carriers horizontally over said ji ger mechanism, a movably mounted cover rame, a source of power, means associated with said cover frame for controlling said source of power, said means being adapted to render the source of power inoperative when the cover frame is raised due to abnormal operation of said mechanism and/or said conveying means.

2. A pottery machine including a plurality of mold carriers, reciprocating jigger mechanism adapted to cooperate with said carriers, means for conveying said carriers horizontallyover said jigger mechanism, a movably mounted cover frame adapted tobe raised upon a departure from normalcy in the 0peration of the machine, a source of power, a

a plurality brake, means associated with said cover frame for controlling the source of power and the rake, said means being so disposed as to render the source of power inoperative when the cover frame is initially raised and for applying said brake upon continued upward movement of the cover frame.

3. A pottery machine including a lurality of molds, means for conveying sai molds, a movably mounted cover frame, reciproca le jigger so arranged as to normally raise said molds without disturbing the cover frame, a. source of power for operating said jigger and said mold conveying means, and means on the cover frame for rendering said source of ower inoperative when the'cover frame is isturbed in the operation of the machine. e

4. A pottery machine including a plurality of molds, means for conveying said molds, a movably mounted cover frame, a jig or for cooperating with said molds, a motor or operating said jigger and said conveying means, a clutch'operatively connecting the motor with the jigger and mold conveying means, and switch and lever means rendered operative through movement of the cover frame for shutting off the power to said motor and for disengaging said clutch.

5. A pottery machine including a plurality of molds, means for conveying movably mounted cover frame, reciprocable means for cooperating with said molds, a source of power for operating said recipr0- cable means and said conveying means, a magnetic brake, and switch and lever means associated with the cover frame for rendering the source of power inoperative and for applying said brake.

6. A pottery machine including a plurality of molds, a conveyor for said molds, a mov-- ably mounted cover. frame associated with the molds, reciprocable means for cooperating with the molds, a motor for operating said reciprocable means and said conveyor, a drive shaft, a clutch operatively connecting the motor with the said shaft, a brake, and switch and lever means associated with the cover frame for disen aging the clutch, shutting off the power to t e motor and applying the brake.

7. A pottery machine including a mold, means for conveying said mold, a profile, means for bringing said-mold and profile into cooperative relationship, a source of power for said machine, and means for rendering said source of power inoperative upon the creation of an excessive pressure between in the mold. pottery forming machine, the comthe profile and the material 8. In a bination with a conveyor, of mold carriers mounted in series in said conveyor and having a plurality of molds disposed therein, fabricating mechanism mounted above the horizontal plane of movement of said carriers and a vertically said molds, a

izo

reciprocating chucks mounted below said horizontal plane, a main drive shaft and a source of power normally having an operative connection with said shaft, switch and lever means, and means rendered operative through abnormal'movement of said fabricating mechanism and/or said chucks for disconnecting said source of power from said shaft.

9. In a pottery forming machine, the combination with a conveyor, of mold carriers mounted in series in said conveyor, fabricating mechnaism mounted above plane of movement of said carriers and reciprocating chucks mounted below said horizontal plane, a main drive shaft and a source of power normally having an operative connection with said shaft, a brake, and means for automatically applying said brake, said means being rendered operative through abnormal movement of said fabricating mechanism and/or said chucks.

10. In a pottery forming machine, the combination with mold conveying and pottery fabricating mechanism, of means for actuating said mechanism including a drive shaft and a source of power normally havin an operative connection with said shaft, a rake, and means rendered active through abnormal operation of said mechanism for disconnecting said shaft from said source and applying said brake.

11. In a pottery forming machine, the combination with one or a plurality of reciprocable and rotatable chucks, of means for reciprocating and rotating said chucks including a drife shaft and a source of power normally having an operative connection with said shaft, and means rendered operative through retarded or advanced reciprocation of said chucks for disconnecting said shaft from said source.

12. In a pottery forming machine, the combination with a plurality of reciprocable and rotatablechucks, of means for reciprocating and rotating said chucks including a drive shaft and a source of power normally having an operative connection with said shaft, a brake, and means rendered active through retarded or advanced reciprocation of said chucks for applying said brake.

13. A pottery forming machine comprising, in combination, a jigger frame, one or more reciprocating chucks to support molds with material thereon, one or more profiles thereover to shape said material, a shaft to actuate said machine and a source of power to o erate said shaft, and a means for automatically disconnecting said shaft from said source, said means being so disposed as to be kept inactive by the normaloperation of the machine and to be brought into action by a departure from normalcy in the operation of the machine.

14. A pottery forming machine compristhe horizontal ing, in combination, a jigger frame, one or more reciprocating chucks to support molds with material thereon, fabricatin mecha nism mounted above said chucks an adapted to operate on said material, a shaft to actuate said machine, a motor to rotate said shaft and suitable electric conduits for connecting said motor to a source of electric energy, and a means for automatically disconnecting said motor from said source, said means being so disposed as to be kept inactive during the normal operation of the machine and to be brought into action by a departure from normalcy in the operation of the. machine.

15. A pottery forming machine comprising, in combination, one or more jigger spindles with chucks thereon to support molds, fabricating mechanism mounted above said chucks, a shaft to actuate said machine and a source of power to operate said shaft, and a means for automatically disconnecting said shaft from said source, said means comprising a two-part friction clutch and a member operatively connected thereto and so disposed as to maintain the parts of the clutch in engagement during the normal operation of the machine and to disengage said parts upon a departure from normalcy in the operation of the machine.

16. A pottery forming machine comprising, in combination, one or more reciprocating jigger spindles with chucks thereon, a traveling mold carrier thereover, actuate said spindles and a source of power to operate said shaft, and a means for automatically disconnecting said shaft from said source, said means being so disposed as to be actuated by the upward motion of said carrier when the latter is raised by said chucks in the event said chucks are out of registration with said carrier.

17. A pottery forming machine comprising, in combination, one or more reciprocating jigger spindles with chucks thereon, a movable jigger frame to carry said spindles, a traveling mold carrier positioned over said spindles, a shaft to actuate said s indles and a source of power to operate sai shaft, and a means for automatically disconnecting said shaft from said source, said means being so disposed as to be actuated by the upward motion of said carrier when the latter is raised by the upward motion of said chucks in the event the latter are reciprocated out of registration with said carrier.

18. A pottery forming machine comprising, in combination, one or more reciprocat-, ing jigger spindles with chucks thereon, a movable jig er frame for carrying said spindles, a trave ing mold carrier positioned over said spindles, a shaft for actuating said spindles and a source of power for said shaft,

.and a means for automatically disconnecting said shaft from said source, said means being a shaft to a so disposed as to be actuated by the forward motion of said frame the latter.

19. A pottery forming machine comprising, in combination, one or more reciprocating chucks, fabricating mechanism mounted over said chucks, a shaft to actuate said machine and a source of power to operate said shaft, a brake, and a means for automatically disconnecting said shaft from said source and applying said brake, said means comprising a two-part friction clutch and switch upon overrunning of and/or lever means connected thereto and so disposed as to maintain the parts of the clutch in engagement during the normal opto disengage the qucntly apply said brake.

20. In a pottery forming machine, the combination with a plurality of mold carriers, of means for conveying said carriers, a

movably mounted cover frame, a source of power, a brake, means associated with the cover frame for inoperative when the cover frame is initially raised and for applying said brake upon c0ntinued upward movement of the cover frame.

21. In a pottery forming machine, the combination with a plurality of mold carwith said conveying means, mounted cover frame disposed adjacent said mechanism and adapted to be moved in the event of abnormal operation and lack of synchronism of said conveying means and said jigger mechanism, a drive shaft, a source of power having a clutch connection with said shaft, a brake, and means adapted to be operated through movement of the cover frame for releasing the clutch and applying said brake.

WILLIAM J. MILLER.

a movably 

